Change in the methylation pattern of genes involved in energy metabolism after bariatric surgery

Author(s)

Luísa Maria Diani

• Document type: Master's Dissertation
• Press: Ribeirão Preto.
• Institution: Universidade de São Paulo (USP). Faculdade de Medicina de Ribeirão Preto (PCARP/BC)
• Defense date: 2024-06-14

Examining board members

Carla Barbosa Nonino; Jose Rodrigo Pauli; Thiago Vidotto

• Advisor: Carla Barbosa Nonino

Abstract

Introduction: Dietary and surgical treatments for obesity can modulate epigenetic regulation, acting on energy metabolism and altering the transcription of genes underlying oxidative stress, inflammation and metabolic imbalance. Objective: to comparatively analyze the methylation profile of genes related to energy metabolism in pre- and post-bariatric surgery patients. Methodology: Women who underwent Roux-en-Y gastric bypass (RYGB) were selected in the pre- and six-month postoperative periods, with assessment of anthropometric and biochemical indicators, body composition and resting metabolic rate by indirect calorimetry. DNA from whole blood was extracted for DNA methylation analysis, performed using the Infinium HumanMethylation450k Kit. and analyzed by the ChAMP (Chip Analysis Methylation Pipeline) package. Then, the corresponding symbols were inserted into the STRING (Protein-Protein Interaction Network Functional Enrichment Analysis) platform for gene ontology results. Data were presented as mean and standard deviation. The following statistical tests were performed: Shapiro-Wilk test, paired t-test or Wilcoxon test, Pearson or Spearman correlation. The accepted level of significance was p<0.05. Results: 24 women with obesity (37±10.4 years) showed a significant reduction in anthropometric measurements (p<0.0001), biochemical indicators (Glycemia: p=0.0008; TC: p=0.0002; LDLc: p =0.005; Triglycerides: p<0.0001) and TMR (p<0.0001). Bioinformatics analyzes identified some differentially methylated CpG sites in the evaluated genes, and ADRB3 was differentially methylated after six months of bariatric surgery. Functional enrichment revealed that the gene is involved in metabolic pathways such as regulation of lipolysis and thermogenesis. Conclusion: Surgical treatment for obesity promoted a metabolic improvement evidenced by the reduction of anthropometric and biochemical indicators, and provided changes in ADRB3 methylation and energy expenditure in women with grade III obesity after six months of the procedure. (AU)

• FAPESP's process: 22/15068-9 - Change in the methylation pattern of genes involved in energy metabolism after bariatric surgery
• Grantee: Luísa Maria Diani
• Support Opportunities: Scholarships in Brazil - Master